//作业一 LED灯流水
  int max = 13;
  int crossTime = 500;
void setup() {
  // put your setup code here, to run once:
  pinMode(7,OUTPUT);
  pinMode(8,OUTPUT);
  pinMode(9,OUTPUT);
  pinMode(10,OUTPUT);
  pinMode(11,OUTPUT);
  pinMode(12,OUTPUT);
}

void loop() {
  // put your main code here, to run repeatedly:
  for(int x=7;x<max;x++){
    if(x==7){
     digitalWrite(x,HIGH);
     digitalWrite(max-1,LOW);
    }else{
        digitalWrite(x,HIGH);
  digitalWrite(x-1,LOW);
    }
  
  delay(crossTime);
  }
}
